Water Rocket Forum

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A water rocket is a type of model rocket using water as its reaction mass. The pressure vessel (the engine of the rocket) is constructed from thin plastic or other non metallic materials (usually a used plastic soft drink bottle) weighing 1,500 grams or less. The water is forced out by compressed air. It is an example of Newton's third law of motion.

Unfortunately local stores give me limited options, nevertheless instead of the pvc tube I decided to use a fiber reinforced hose with a pvc tube outside. To fix the bike valve I was going to use a clamp but I saw another part that gave me an idea, it was a cable gland and I gave it a try. The bike valve fits very well inside the gland and I screw it to the hose ( not the best solution .. but just to try).

It worked at 70 and 100psi .. but was loosing 1-2psi/min through the screw zone. So I assembly it again using glue and after repeating the two 15 min tests, was loosing only 0-0,2psi/min. I think I have a launcher

Afterwards just did a few improvements on it and now I have to build a rocket to launch. I still do not have one ..

Congrats! Good job on finding a work around to limited options. I know I've left my local hardware guys scratching their heads more than a few times. Good luck on your rocket build!

Unfortunately local stores give me limited options, nevertheless instead of the pvc tube I decided to use a fiber reinforced hose with a pvc tube outside. To fix the bike valve I was going to use a clamp but I saw another part that gave me an idea, it was a cable gland and I gave it a try. The bike valve fits very well inside the gland and I screw it to the hose ( not the best solution .. but just to try).

It worked at 70 and 100psi .. but was loosing 1-2psi/min through the screw zone. So I assembly it again using glue and after repeating the two 15 min tests, was loosing only 0-0,2psi/min. I think I have a launcher

Afterwards just did a few improvements on it and now I have to build a rocket to launch. I still do not have one ..

Your cable gland looks a bit like another idea we used in the past when we didn't have any end caps and didn't have time to go the store. We had a reducer fitting that had 1/2" threads on one side and 1/4" threads on the other. The tire valve would fit inside the half inch side and the rubber flange that goes into the rim was too fat to pass out the 1/4 inch side, so it worked pretty well in a pinch and didn't look like there was any way it would come apart.

Plus, the more pressure that was put in, the tighter it would make itself.